免疫相关基因FGF13、GZMB、FLT3、CRLF3可能与急性髓系白血病患者预后密切相关

为了构建急性髓系白血病（AML）患者的预后风险模型,本研究通过IMMPORT数据库提取免疫基因,通过基因表达综合（GEO）数据库和AML相关转录组RNA测序数据集筛选差异表达的免疫基因,基于癌症基因组图谱（TCGA）数据库下载AML相关的表达谱数据集（TCGA-LAML）及临床数据,对差异表达的免疫基因进一步进行单因素COX回归分析和多因素COX回归分析,最终确定了关键免疫基因,随后根据免疫基因进行单基因预后分析以及免疫浸润分析。结果显示：与正常对照组相比,在AML患者的骨髓样本中,有55个免疫基因显著上调或下调,其中由4个免疫基因（FGF13、GZMB、FLT3、CRLF3）构建的风险模型能预测AML患者的预后[曲线下面积（AUC）=0.741];高风险组和低风险组之间免疫细胞的含量存在显著差异,其中FGF13、CRLF3为低风险基因,GZMB、FLT3为高风险基因。这为4个免疫基因FGF13、GZMB、FLT3、CRLF3及其构建的风险模型用于监测AML患者的预后和免疫浸润情况提供了理论基础。     

基于生物信息学分析Notch3通路在胃肠道肿瘤中预后作用

本文旨在探讨Notch3通路基因在胃肠道肿瘤中预后的作用。通过Timer和GEPIA数据库在泛癌水平探索Notch3表达模式;利用GEO数据库中GSE31168和GSE11417芯片数据集,基于Spearman相关性分析和差异表达分析,对Notch3通路关键基因进行筛选;基于TCGA-STAD和TCGA-COAD数据集探索Notch3表达水平和胃癌、结肠癌患者生存的关联;应用Notch3特征基因进行胃癌和结肠癌风险评估模型构建。结果显示,Notch3在胃癌和结肠癌组织中的表达均高于对照的。胃癌Notch3表达水平与DLL1、DLL3、HEY1、HEYL、FLT4成正相关性,且Notch3、DLL1、DLL3、HEY1、HEYL、FLT4的高表达也与胃癌的预后不良呈正相关。利用结肠癌GSE11417研究表明,结肠癌Notch3表达水平与DLL1、DLL3、HEYL、FLT4成正相关性,且Notch3、DLL1、DLL3、HEYL、FLT4的高表达与结肠癌的预后不良成正相关。依据Notch3、DLL1、DLL3、HEYL和FLT4特征基因,构建的胃癌和结肠癌风险评估模型在TCGA中具备预后...     

APL的发病分子机制和治疗进展

急性前髓细胞性白血病(APL)是急性髓细胞样白血病(AML)的一个亚型,它的分子生物学特征为95%的患者有15号染色体前髓细胞性白血病基因(PML)与17号染色体视黄酸受体(RARα)基因的融合易位表达.维甲酸(ATRA)单药治疗能使APL患者达90%的缓解率,化疗药物与ATRA的联合应用更能降低患者复发率,改善生存;三氧化二砷(ATO)能使复发患者缓解率达到90%.这篇文章主要综述APL的发病分子机制和治疗进展.     

基因测序法检测FLT3和NPM1的突变研究

目的:基因测序法检测FLT3和NPM1突变在急性髓系白血病(AML)中预后判断和分子靶向治疗的意义。方法:利用基因测序法检测35例急性髓系白血病的突变。结果:发现35例样本中FLT3-ITD突变4(13.3%)例,NPM1突变6(20%)例,没有发现FLT3和NPM1都突变,其它25(71.4%)例均为FLT3阴性、NPM1阴性。结论:AML存在NPM1突变958bp处出现插入突变,缺失TGGCAGTG和缺失后替换成gcccgcggttta的突变,FLT3中出现内部串联重复突变,直接测序法最方便检测此突变。     

急性髓系白血病铁死亡相关基因筛选及预后模型的建立

基于急性髓系白血病(Acute Myeloid Leukemia,AML)临床大数据及多组学数据库探讨铁死亡相关基因在AML中的作用,并建立铁死亡基因表达相关预后模型。整合TCGA数据库中151例AML患者和GTEx数据库中337例正常人外周血的临床和转录组数据。将Wilcoxon检验和单因素Cox分析结果取交集,筛选出预后相关差异表达基因(Differential Expression Genes, DEGs),使用Lasso回归建立基因标志物预后模型,利用受试者工作特征曲线(Receiver Operating Characteristic Curve,ROC曲线)评价预测价值,Kaplan-Meier法进行生存分析,对AML患者临床数据进行单因素和多因素Cox回归分析,使用差异基因表达分析等方法比较高、低风险患者间的组学差异,最后,利用BeatAML数据库对基因标志物进行验证。将差异基因表达分析和单因素分析结果取交集,得到13个预后相关DEGs。构建了8个基因标志物的预后评分模型,并将患者分为高、低风险两组;ROC曲线分析证实了模型良好的预测性能;生存分析提示高、低风险组患者的生存率具有显著差异;单因素分析显示年龄和风险评分与患者整体生存显著相关,多因素分析显示,年龄和风险评分是独立预后指标。在2个风险组之间筛选出384个DEGs,GO富集分析结果显示,富集的基因大多与中性粒细胞和白细胞的趋化与迁移等免疫相关分子和通路显著相关,KEGG富集通路主要与TNF信号通路、细胞因子与细胞因子受体相互作用相关。BeatAML数据库验证结果显示,5个基因与预后显著相关。铁死亡相关基因在AML中显著表达,且高风险患者预后较差,该研究对AML铁死亡相关潜在生物标志物的发现和应用奠定了一定的基础。     

基于ONCOMINE数据库荟萃分析BRCA1基因在肺癌中的表达及意义

为探讨BRCA1基因在肺癌中的表达及对肺癌患者预后生存意义,本研究利用(BioGPS, Oncomine,Kaplan-Meier Plotter)基因数据库和癌症细胞系百科全书(CCLE),分析BRCA1基因在正常人体组织中的表达以及差异表达情况,并对符合条件的研究进行Meta分析,同时分析BRCA1基因在肺癌组织细胞系中的表达和对肺癌患者预后生存意义。研究发现,BioGPS数据库显示BRCA1在正常肺癌组织中低表达(3.65±0.035);同时Oncomine数据库检索BRCA1基因有453项不同种类结果,35项结果表达有统计学差异意义,其中28项显示表达增高,7项显示表达降低,共有研究样本量229例;并对符合条件的5项研究进行Meta分析,发现BRCA1基因差异表达中位数值排名为34.0,p=2.51×10~(-5);与CCLE检索BRCA1基因在肺癌组织细胞系中高表达的结果一致;Kaplan-Meier Plotter数据库检索结果表明BRCA1表达水平与患者的总生存预后周期相关(p=9.5×10~(-6));并且BRCA1高表达组相对于低表达组的肺癌患者总体生存周期明显降低(p0.05)。因此,通过深入挖掘Oncomine等数据库中BRCA1基因芯片信息,证实BRCA1基因在肺癌组织中呈现高表达状态,且与肺癌患者预后生存周期相关,为临床肺癌的治疗及基因靶向药物的研制提供重要依据。     

基于TCGA与Oncomine数据库挖掘MKL-1基因在KIRC中的临床意义

[目的]阐明MKL-1基因在肾透明细胞癌中的表达情况与临床意义。[方法]从TCGA与Oncomine数据库中收集与MKL-1的表达相关的数据,对收集到的数据进行荟萃分析,同时使用Kaplan–Meier方法分析MKL-1的表达量与生存的相关性。[结果]从Oncemine数据库中共收集到154项与MKL-1有关的研究,分析表明在MKL-1在9种癌症中表达上升,且在肾透明细胞癌中的表达显著性上升(P 0. 05)。进一步分析发现MKL-1与癌症患者的特征无显著性关系,但与预后成负相关性。最后通过蛋白质网络预测MKL-1相互作用的蛋白。[结论]基于不同数据库深度挖掘提示MKL-1基因在肾透明细胞癌中高表达,并与肾透明细胞癌的预后有显著相关性,有望被用作肾透明细胞癌的治疗的新靶点。     

Oncomine数据库在肿瘤研究中的应用

Oncomine 是目前世界上最大的癌基因芯片数据库和综合数据挖掘平台之一,该数据库整合了GEO、TCGA和已发表文献来源的RNA和DNA-seq数据。数据库目前含有715个基因表达数据集（datasheet）、86 733个人体肿瘤组织和正常组织样本的信息,且有新的数据不断更新。Oncomine 数据库囊括的肿瘤类型有19种,包括：膀胱癌、脑/中枢神经系统肿瘤、乳腺癌、宫颈癌、结直肠癌、食管癌、胃癌、头/颈肿瘤、肾癌、白血病、肝癌、肺癌、淋巴瘤、黑色素瘤、骨髓瘤、卵巢癌、胰腺癌、前列腺癌、肉瘤。本文就如何利用Oncomine数据库,进行肿瘤组织中癌基因表达差异性分析以及基因共表达分析、癌基因在肿瘤组织中的表达及拷贝数分析、多组研究数据集的荟萃分析（meta analysis）、以及癌基因表达与患者生存率关系等进行分析。通过该数据库可以对肿瘤癌基因进行研究前的筛查,有利于发现新的肿瘤生物标记物或治疗靶点,为临床科学研究奠定一定的理论基础。     

Daxx在急性白血病的表达及意义

目的研究Daxx在急性白血病(AL)中的表达及其与AL的分型、临床特征、疗效及预后的关系.方法应用免疫组织化学方法检测88例初治AL骨髓细胞Daxx蛋白的表达情况,分析其与FAB分型、临床特征、疗效及预后的关系.结果急性髓细胞白血病(AML)骨髓细胞中Daxx的表达显著高于正常对照组(P<0.05)与急性淋巴细胞白血病(ALL)组(P<0.05).在AML亚型中,Daxx在M3中的表达显著高于M1,M2,M3,M4和M5.采用逐步回归法分析,校正其它参数,Daxx的表达与初诊时的白细胞数及骨髓原始细胞数目呈正相关,与疗效呈负相关. 结论 Daxx在急性髓细胞白血病中广泛表达,其表达的紊乱可能在AML的发病中起作用,还与AML的某些临床特征、疗效及预后密切相关.     

Over-expression of FoxM1 is associated with adverse prognosis and FLT3-ITD in acute myeloid leukemia

Forkhead box M1 (FoxM1) drives cell cycle progression and the prevention of growth arrest and is over-expressed in many human malignancies. However, the characteristics of FoxM1 in acute myeloid leukemia (AML) are not clearly understood. We investigated the expression level of FoxM1 and analyzed the correlation of FoxM1 expression with AML patient characteristics and prognoses. Changes in FoxM1 expression were detected after MV4–11 cells, which have an internal tandem duplication (ITD) of the fms-like tyrosine kinase 3 gene (FLT3-ITD), and control THP1 cells (encoding wild-type FLT3) were treated with the FLT3 receptor tyrosine kinase inhibitor AC220 (quizartinib) or FLT3 ligand (FL). Finally, we determined the apoptosis rates after the addition of the FoxM1 inhibitor thiostrepton (TST) to AML cells with or without FLT3-ITD. The expression of FoxM1 in AML patients was correlated with the presence of FLT3-ITD, genetic groups, and possibly overall survival. Inhibition of FLT3-ITD by AC220 down-regulated FoxM1 expression in MV4–11 cells, and stimulation of FLT3 by FL up-regulated FoxM1 expression in MV4–11 and THP1 cells. TST induced the apoptosis of MV4–11 and THP1 cells in a dose-dependent manner. Thus, FoxM1 is a potential prognostic marker and a promising therapeutic target in AML.     

RUNX1 mutation and elevated FLT3 gene expression cooperates to induce inferior prognosis in cytogenetically normal acute myeloid leukemia patients

BackgroundAcute myeloid leukemia (AML) is a bone marrow malignancy having multiple molecular pathways driving its progress. In recent years, the main causes of AML considered all over the world are genetic variations in cancerous cells. The RUNX1 and FLT3 genes are necessary for the normal hematopoiesis and differentiation process of hematopoietic stem cells into mature blood cells, therefore they are the most common targets for point mutations resulting in AML.MethodsWe screened 32 CN-AML patients for FLT3-ITD (by Allele-specific PCR) and RUNX1 mutations (by Sanger sequencing). The FLT3 mRNA expression was assessed in all AML patients and its subgroups.ResultsEight patients (25%) carried RUNX1 mutation (K83E) while three patients (9.37%) were found to have internal tandem duplications in FLT3 gene. The RUNX1 mutation data were correlated with clinical parameters and FLT3 gene expression profile. The RUNX1 mutations were observed to be significantly prevalent in older males. Moreover, RUNX1 and FLT3-mutated patients had lower complete remission rate, event-free survival rate, and lower overall survival rate than patients with wild-type RUNX1 and FLT3 gene. The RUNX1 and FLT3 mutant patients with up-regulated FLT3 gene expression showed even worse prognosis. Bradford Assay showed that protein concentration was down-regulated in RUNX1 and FLT3 mutants in comparison to RUNX1 and FLT3 wild-type groups.ConclusionThis study constitutes the first report from Pakistan reporting significant molecular mutation analysis of RUNX1 and FLT3 genes including FLT3 expression evaluation with follow-up. This provides an insight that aforementioned mutations are markers of poor prognosis but the study with a large AML cohort will be useful to further investigate their role in disease biology of AML.     

MicroRNA-16 Is Down-Regulated in Mutated FLT3 Expressing Murine Myeloid FDC-P1 Cells and Interacts with Pim-1

Activating mutations in the receptor tyrosine kinase FLT3 are one of the most frequent somatic mutations in acute myeloid leukemia (AML). Internal tandem duplications of the juxtamembrane region of FLT3 (FLT3/ITD) constitutively activate survival and proliferation pathways, and are associated with a poor prognosis in AML. We suspected that alteration of small non-coding microRNA (miRNA) expression in these leukemia cells is involved in the transformation process and used miRNA microarrays to determine the miRNA signature from total RNA harvested from FLT3/ITD expressing FDC-P1 cells (FD-FLT3/ITD). This revealed that a limited set of miRNAs appeared to be affected by expression of FLT3/ITD compared to the control group consisting of FDC-P1 parental cells transfected with an empty vector (FD-EV). Among differentially expressed miRNAs, we selected miR-16, miR-21 and miR-223 to validate the microarray data by quantitative real-time RT-PCR showing a high degree of correlation. We further analyzed miR-16 expression with FLT3 inhibitors in FLT3/ITD expressing cells. MiR-16 was found to be one of most significantly down-regulated miRNAs in FLT3/ITD expressing cells and was up-regulated upon FLT3 inhibition. The data suggests that miR-16 is acting as a tumour suppressor gene in FLT3/ITD-mediated leukemic transformation. Whilst miR-16 has been reported to target multiple mRNAs, computer models from public bioinformatic resources predicted a potential regulatory mechanism between miR-16 and Pim-1 mRNA. In support of this interaction, miR-16 was shown to suppress Pim-1 reporter gene expression. Further, our data demonstrated that over-expression of miR-16 mimics suppressed Pim-1 expression in FD-FLT3/ITD cells suggesting that increased miR-16 expression contributes to depletion of Pim-1 after FLT3 inhibition and that miR-16 repression may be associated with up-regulated Pim-1 in FLT3/ITD expressing cells.     

Inhibition of FLT3 Expression by Green Tea Catechins in FLT3 Mutated-AML Cells

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by a block in differentiation and uncontrolled proliferation. FLT3 is a commonly mutated gene found in AML patients. In clinical trials, the presence of a FLT3-ITD mutation significantly correlates with an increased risk of relapse and dismal overall survival. Therefore, activated FLT3 is a promising molecular target for AML therapies. In this study, we have shown that green tea polyphenols including (−)-epigallocatechin-3-gallate (EGCG), (−)-epigallocatechin (EGC), and (−)-epicatechin-3-gallate (ECG) suppress the proliferation of AML cells. Interestingly, EGCG, EGC and ECG showed the inhibition of FLT3 expression in cell lines harboring FLT3 mutations. In the THP-1 cells harboring FLT3 wild-type, EGCG showed the suppression of cell proliferation but did not suppress the expression of FLT3 even at the concentration that suppress 100% cell proliferation. Moreover, EGCG-, EGC-and ECG-treated cells showed the suppression of MAPK, AKT and STAT5 phosphorylation. Altogether, we suggest that green tea polyphenols could serve as reagents for treatment or prevention of leukemia harboring FLT3 mutations.     

Combined effects of FLT3 and NF-κB selective inhibitors on acute myeloid leukemia in vivo

FMS-like tyrosine kinase 3 (FLT3) is an independent poor prognostic marker of acute myeloid leukemia (AML), and strategies that specifically target FLT3 are therefore of substantial interest. However, previous studies with FLT3 inhibitors as single agents in patients with AML showed few clinical responses. In the present study, combined effects of FLT3 selective inhibitor (SC-203048) and NF-κB selective inhibitor (Parthenolide, PTL) on AML xenograft tumor growth in vivo were examined, and the possible antitumor mechanisms by which SC-203048 and PTL affect AML xenograft tumor growth were also detected. Results showed that the tumor growth was strongly inhibited, and increased cell apoptosis was also observed after treatments, especially in the combination group; meanwhile, the expressions of FLT3, p65, cyclin D1, and Bc1-2 decreased significantly, and the expression of nuclear Silencing mediator for retinoic acid and thyroid hormone receptors (SMRT) increased notably. All results indicate that synergism exists between FLT3 and NF-κB inhibitors, and inhibitors combination treatment may be a potential strategy for AML.     

FLT3/ITD mutation signaling includes suppression of SHP-1

Mutations in the FLT3 gene are the most common genetic alteration found in AML patients. FLT3 internal tandem duplication (ITD) mutations result in constitutive activation of FLT3 tyrosine kinase activity. The consequences of this activation are an increase in total phosphotyrosine content, persistent downstream signaling, and ultimately transformation of hematopoietic cells to factor-independent growth. The Src homology (SH)2 domain-containing protein-tyrosine phosphatase (SHP)-1 is involved in the down-regulation of a broad range of growth factor and cytokine-driven signaling cascades. Loss-of-function or deficiency of SHP-1 activity results in a hyperproliferative response of myelomonocytic cell populations to growth factor stimulation. In this study, we examined the possible role of SHP-1 in regulating FLT3 signaling. We found that transformation of TF-1 cells with FLT3/ITD mutations suppressed the activity of SHP-1 by approximately 3-fold. Suppression was caused by decreased SHP-1 protein expression, as analyzed at both the protein and RNA levels. In contrast, protein levels of SHP-2, a phosphatase that plays a stimulatory role in signaling through a variety of receptors, did not change significantly in FLT3 mutant cells. Suppressed SHP-1 protein levels in TF-1/ITD cells were partially overcome after cells were exposed to CEP-701, a selective FLT3 inhibitor. SHP-1 protein levels also increased in naturally occurring FLT3/ITD expressing AML cell lines and in primary FLT3/ITD AML samples after CEP-701 treatment. Furthermore, a small but reproducible growth/survival advantage was observed in both TF-1 and TF-1/ITD cells when SHP-1 expression was knocked down by RNAi. Taken together, these data provide the first evidence that suppression of SHP-1 by FLT3/ITD signaling may be another mechanism contributing to the transformation by FLT3/ITD mutations.